<div class="container">
  <ul class="pics">
    <li class="pic" *ngFor="let pic of pics;index as i;">
      <img [src]="pic" [ngClass]="{'active':activeIndex==i}" (click)="onImageClick()"/>
    </li>
  </ul>
  <div class="prev" (click)="onPrev()" *ngIf="activeIndex>0">&lt;</div>
  <div class="next" (click)="onNext()" *ngIf="activeIndex<pics.length-1">&gt;</div>
</div>
